Open the driver side door. Up by the fender riveted to the pillar.
There is no vin number located anywhere on the frame of a 69 impala
http://www.decodethis.com/164679U223937
as far as I know there is no vin# on the frame.
frame
in the door jam
I don't believe there is a vin# on the frame, it's on the drivers door front pillar.
The vin # is located on the driver side of the cowl above the brake master cylinder/brake booster on the cowl tag. The 1968 chevy vin # does not have a letter or # that tells if the car is a super sport or not. 1967 was the last year that an impala ss was identified in the vin #.
it should be on either the drivers door or on the glove compartment lid
5x4.75
300
66 Impala bolt pattern is 5X4 3/4
Impalas Bob's will sell you a hard copy of the 1966 Impala wiring diagram for $9.99. Alternatively you could check out the DIY Repair Manual site that sell complete service manuals including the wiring diagrams.